1. Field of the Invention
The present invention relates to an apparatus for preventing discharge of fuel vapor; and more particularly, to an apparatus for preventing such discharge from a vehicle fuel tank which is made to communicate with a charcoal canister via a vent tube at times when a fuel lid is opened by a fuel lid opener, for causing fuel vapor to be adsorbed by the charcoal canister.
2. Description of the Related Art
A conventional for preventing discharge of fuel vapor from a vehicle fuel tank to the atmosphere when the fuel tank is being filled is apparatus disclosed in Japanese Patent Laid-Open No. 41244/1988.
This apparatus has a vent tube connecting the fuel tank to a charcoal canister for adsorbing fuel vapor. A solenoid valve which is disposed midway in the vent tube is normally closed when the fuel lid is closed (locked state). A switch detects the actuation of the fuel lid opener and opens the solenoid valve.
Accordingly, at the time of refueling, if the locked fuel lid is operated to the unlocked state by operating a lid opener lever, the actuation detecting switch is turned on, which, in turn, causes the solenoid valve in the vent tube to open, thereby allowing fuel vapor in the fuel tank to flow into charcoal canister via the vent tube for adsorption by the charcoal in the canister. As a result, it is possible to prevent the fuel vapor from being discharged via the inlet pipe (filler pipe) to the atmosphere during refueling.
This prior apparatus for preventing discharge of fuel vapor, uses an actuation detecting switch as shown in FIG. 7, wherein, an actuation detecting switch 90 is disposed midway in a wire tube 92 covering a wire 94, which connects the lid opener lever to a fuel lid locking device. The opening and closing of actuation detecting switch 90 is controlled by an actuator 96 fixed to the movable wire 94.
Accordingly, after a fuel lid locking device is mounted to an automobile body, it is necessary to adjust the position of the wire tube 92 relative to the wire 94 so as to detertmine the relative position of the actuation detecting switch 90 and the actuator 96. This position complicates the adjusting operation, and decreases the operating efficiency of assembly. In addition, even the fixing of a magnet to the wire and a lead switch to the wire tube does not make the adjusting operation any less complicated than the one described above.